asterisk users - Dec 2004 - It's possible to do a codecs translation during a call in Asterisk?

Hi everyone,

We are using the IAXy boxes and Asterisk over the internet and I was
wondering if Asterisk can do a codec translation during a call in order
to lower the bandwidth that the comunications consumes?

I mean, the IAXy boxes only support the ADPCM and uLAW codecs, but for a
certain number of calls our bandwidth runs out, then I think if Asterisk
can convert the signal that comes in ADPCM format (the lighter codec out
of these two) to another codec that use less bandwidth to interconect to
another Asterisk Server via IAX2 protocol.

We are trying not to upgrade our 30 internet connections because the
cost of it will be multiplyed by 30 (obiously).

Thanks in advance for all,

Ra?l.

Ra?l G?mez Cabrera wrote:
> Hi everyone,
> 
> We are using the IAXy boxes and Asterisk over the internet and I was
> wondering if Asterisk can do a codec translation during a call in order
> to lower the bandwidth that the comunications consumes?
> 
> I mean, the IAXy boxes only support the ADPCM and uLAW codecs, but for a
> certain number of calls our bandwidth runs out, then I think if Asterisk
> can convert the signal that comes in ADPCM format (the lighter codec out
> of these two) to another codec that use less bandwidth to interconect to
> another Asterisk Server via IAX2 protocol.
> 
> We are trying not to upgrade our 30 internet connections because the
> cost of it will be multiplyed by 30 (obiously).
First a couple of keys, so we know we're talking about the same things.

Your setup (as I understand it) is:

IAXy -> Asterisk A --IAX--> Asterisk B

The easiest way would be:

Asterisk A should have accounts in iax.conf for the IAXy's and the IAX 
link to Asterisk B.

In the section for the link to Asterisk B, put:

disallow=all
allow=gsm

and do the same in Asterisk B's iax.conf file for the Asterisk A entry.

That way you will end up with:

IAXY --adpcm IAX--> Asterisk A --GSM IAX--> Asterisk B

Asterisk A will convert from adpcm to GSM and the link between will use 
this.  That way you have highest quality on your LAN (where bandwidth is 
unimportant) and then a compressed codec for traversal of the WAN (where 
bandwidth is obviously more important).

Make sense?  :-)

-- 
Cheers,

Matt Riddell
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Hi Matt,

I have a coupple of question yet,
>First a couple of keys, so we know we're talking about the same things.
>
>Your setup (as I understand it) is:
>
>IAXy -> Asterisk A --IAX--> Asterisk B

Ok, as I see my current setup is:

          LAN                Internet                LAN
(IAXy A) ----> (Asterisk A) ---IAX2--> (Asterisk B) ----> (IAXy B)
         ADPCM                 ADPCM                ADPCM

>
>The easiest way would be:
>
>Asterisk A should have accounts in iax.conf for the IAXy's and the IAX 
>link to Asterisk B.
>
I have in the iax.conf of Asterisk A: 

  "register => userA:pass@www.mysite_B.com:4569"

and in the iax.conf of the Asterisk B:

  "register => userB:pass@www.mysite_A.com:4569"

is that what you mean by "account for the IAX link"? if not please
tell
me the correct way to do so.

>In the section for the link to Asterisk B, put:
>
>disallow=all
>allow=gsm
>
>and do the same in Asterisk B's iax.conf file for the Asterisk A entry.
>
>That way you will end up with:
>
>IAXY --adpcm IAX--> Asterisk A --GSM IAX--> Asterisk B
>
>Asterisk A will convert from adpcm to GSM and the link between will use
>this.  That way you have highest quality on your LAN (where bandwidth
is 
>unimportant) and then a compressed codec for traversal of the WAN
(where 
>bandwidth is obviously more important).
>
>Make sense?  :-)
YES! that makes a lot of sense and I think we are talking about the same
think! :-D

Thanks!!!
>
>-- 
>Cheers,
>
>Matt Riddell
>
--
Ra?l G?mez Cabrera